Tanning apparatus.



No. 637,42l. Patented Nov. 2|, |899.

H. SCHMIDT & J. LANDINI.

TANNlNG APPARATUS.

Application led Sept. 15, 1896.)

(No Model.)

UNrrnn STATES PATENT Frisia.

HERMANN SCHMIDT AND JULES LANDINI, OF HAMBURG, GERMANY.

TANNING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 637,421, dated November 21, 1899-. Application filed September 15, 1896. Serial No. 605,945. (No model.)

To all wher/t it may concern.-

Be it known that we, HERMANN SCHMIDT, manufacturer, a subject of the Emperor of Germany, and JULES LANDINI, merchant, a citizen of the French Republic, residing at Hamburg, Germany, have invented certain new and useful Improvements in Processes of and Apparatus for Tanning Green Hides; and the invention consists in the improved process and the novel construction of the apparatus employed in carrying out said improved process, as hereinafter fully described and claimed.

The same invention has already been patented by us in the Empire of Germany, Patent No. 92,364 of 1897, and in the Kingdom of Great Britain, Patent No. 13,686, June 20, 1896.

In the drawings hereto annexed, Figure 1 is a vertical longitudinal sectional view of a series of revolving drums, their operatinggearing, the heaters, the tank for heating the tannic acid, the collecting-tank for receiving the heated tannic acid, and the valved oonnecting-pipes of the apparatus; and Fig. 2 is an enlarged sectional view of a portion of one of the revolving drums disconnected or detached from the plant or series of connected revolving drums.

Referring by letter to the accompanying drawings, the apparatus byv which this process is carried out in the present instance comprises a set or series of four dums A, B, C, and D, which are supported in suitable bearings in the upper ends of the vertical standards H I', H2 J 2, H3 J 3, and H4 J 4 and are revolved by any suitable power. Each of the revolving drums A, B, C, and D is connected with the supply-tank M N through the pipe E, which is provided with the air-pipe D', having the valve Z. The pipe E has the valved branch pipes c' c2 c3 c4, provided with stop-cocks or valves Q Q2 Q3 Q4 above the horizontal branch pipes d cl2 d2 d4 and stop-cocks or valves R R2 R2 R4 between the heaters F F2 F3 F4. The pipes d d2 d2 d4 connect with conducting-tubes ct a2 d2 a4, which enter the drums through hollow axes in the left ends of said drums and pass upwardly and quite to the opposite ends of said drums between the exterior wall of said drum-s and their perforated linings Z Z2 Z3 Z4. From these drums A B C D pipes b' b2 b3 b4, between the perforated linings Z Z2 Z2 Z4, lead out the hollow axes at the right ends of said drums through valved pipes ff2 f3f4 and connectwith the vertical valved pipes g g2 g3 g4,which are connected at their lower ends with the wastepipe O. The pipes f f2 f3 are also connected with the lower ends of the heaters F2 F3 F4, provided with heating-coils within, by val ved pipes h /t2 h2 in order that the tannic acid used to tan the hides may be heated in its passage through the heaters to the drums,the heat being supplied from any suitable source through the pipe G to the heaters. The heaters F' F2 F2 F4 are also connected with the draw-off or waste pipe O, so that the water of condensation maybe drawn off through the same. The heaters F F2 F2 F4, containing the steam-coils connected with the steam-pipe, are connected with valved circulating-pipes e' e2 e2 e4,through which the tannic acid may be conducted to either of the revolving drums at the will of the attendant.

rLhe drums are provided with doors,through which the hides may be entered and removed.

It should be understood thatthe fresh skins are first placed in any one of the revolving drums, which are all connected, as described, and in whichever drum the skins are first placed they are subjected to the action of the weaker tannic acid. The skins thus treated are subjected progressively to the action of a stronger tannic acid in the next drum, and by the next drum is meant either one of the series that may contain the tannic acid of the properly-increased strength, not necessarily the drum B or the drum Gor the drum D, but any one of them, as the strength of the tannic acid therein may suggest, as any one of said drums may be put in action or cut out of action by the proper cocks or valves when necessary. It should be understood that the fresh skins are placed first in one of the revolving drums containing a weak acid and there subjected to the action of this weak acid. The skins thus treated are then removed froin the rst or initial drum containing the weak tannic acid and placed in another drum of the set containing a stronger tannic acid than contained in the 'rst drum. The skins after being subjected to the action of the stronger tannic acid in the second drum are then removed from the second drum and placed in a third revolving drum containing a still stronger tannic-acid liquid, and thus on throughout the entire set of drums. When the tannic acid in the drums becomes weakened from frequent use, the weakened acid is strengthened to the proper degree by the addition of fresh tannic acid to the weakened tannic acid in whichever drum it may have become weakened. The skins in drum Ahaving been subjected to partial tanning, the valve Z of the air-pressure pipe D is opened,and by opening at the proper time the valves Q' and @air-pressure is admitted to the drums A and C. The overpressure produced in these drums and the solution in drum C being weakened from having acted on the fresh skins to which it has communicated its tannin is forced through the waste-pipe 0, the tubes f3 g3, and valves S3 and Y3 into the draw-off pipe Z, which conducts the tannic acid to the next revolving drum in which it is to be utilized. The tannic acid in thedruin A having been reduced in strength by having been relieved of its tannin through imparting it to the skins passes orfiows through the waste-pipe C', the tubes f' g, valves S" tube 7L', heater F2, valve R2, tube d2, and conducting-tube a2 into drum B. From the drum B the solution which formerly possessed middle strength and has imparted its tannin to the skins is forced into the drum C. The valve Z being now closed, new ooze or tannic acid of a power stronger is conducted from the collecting-tank M through the tubes E c2, valve Q2, tube a2, and the entrance-tube into drum B, the skins in said drum having been first subjected to the action of a medium tannic acid, the latter being brought by the waste-pipe h2, tubes f2 g2, valve T2, tube h2, heater F3, valve R3, tube (Z2, and conductingtube a3 to the drum C, while the weak tannic acid is passed from drinn C to drum D, the latter having in the meantime been provided with fresh skins and placed in operation. The ooze in the drums B C D after having acted on the skins lying in the drums a sufficient length of time and having partially tanned the skins the valve F of the air-pressure pipe and the valves Q2 and a4 are opened and the tannic acid in the drum D, which has not delivered all of its tannic acid to the skins, is forced by air-pressure through the waste-pipe C4, tubes f4 g4, and valves S4Yl into the draw-off pipe, through which it is led off for further use, while the tannic acid in drum B, which has been reduced to middle concentrating power, is forced into the drum C after having first closed the valve Q". The tannic acid which is of low concentration is now forced into the drum D. The drum A after having been relieved of its partially-tanned skins and having been provided with fresh skins is followed by the drum D, which is placedin operation, and a stronger tannic acid is conducted thereto from the collecting-tank M (the valve Z being closed) through the tubes E c3, valve Q3, tube d2, and the conductor a2 into the drum C, so that the tannic acid of middle strength is forced from C to D, while the tannic acid in drum D, being of weaker power, passes through the waste-pipe C4, tubes f4 g4, and valves S4 T4 into the pipe U and through this pipe into the heater F', and from there through the tube e', valve R', tube d', and the tube-entrance ct into the drum A in order to act therein upon fresh skins. The drum B is in the meanwhile put out of operation in order that the nished skins may be removed to make room for fresh ones. In this described manner the drums are put out of operation one after the other and when kept in use are furnished at first always with the weaker tannic acids, which are gradually increased in strength, so that the skins in the drums are subjected to tannins graduallyincreased in strength as the skins are changed from one drum to another.

Nearto and in front of each drum there is provided a heater F F2 F3 F4, hereinbefore described, through which the tannic acid must pass before its entrance into the drum in order that the tannic acid may be lnore or less warmed, which is essential in the process. The warming is effected by the steam-coils S S2 S3 S4, receiving their steam from a steamcoil.

The water-pipe lV is provided with valves X X2 X3 X4 and tubes 7L 71,2 h3 h4, connected with the heaters for the purpose of supplying water to the solution of tannic acid, if it be necessary, to dilute the tannic acid to regulate its strength.

As hereinbefore described, the drums AB C D have perforated edges Z Z2 Z3 Z4. In the annular spaces between the edges and the drumwall are entrance-tubes a a2 a3 a and the waste-pipes Z2' b2 b2b4. The perforated edges serve to distribute the entering tannic acid quite evenly to the contents of the drums and to retain small particles of flesh that become loosened from the hides, and also any other small unclean substances that may have adhered to the hides and have been loosened therefrom during treatment, and thus separate them therefrom before the tannio acid is forced into thenext drum. yWhen the tanning has been completed, these unclean substances may be removed from the drums.

Having thus fully described our invention, what we claim, and desire to secure by Letters Patent, is-

In an apparatus for tanning green hides, the combination with revolving drums,stationary heaters, and a tannic-acid tank; of valved connecting-pipes so disposed that the tannicacid solution in the tannic-acid tank may be changed from drum to drum, and from the tannic-acid tank to the drums, with or without passing through the heaters, substantially as and for the purpose set forth.

In witness whereof we have hereunto set our hands in presence of two witnesses.

HERMANN SCHMIDT. JULES LANDINI.

lVitnesses:

E. H. L. MUMMENHOFF, CnAs. A. BURKE.

IIO 

